Update....I opened case with symantec. It turns out that in Data Source (ODBC) was not connected to our SQL server.
And, 18GB was too small.
We did two things
1. Add MS SQL Database to Data Source in the SEMP Server
2. Free up total of 30GB disk space
Now it works
SMLatCST and SameerU - we will check the autogrowth in SQL
EDIT:
There is one more thing I did - connect to SEPM server using console session, i.e.
mstsc /v:ip address of server /admin